Circuit interrupter



Dec. 4, 1956 R. E. FRIEDRICH 2,773,155

CIRCUIT INTERRUPTER Filed Nov. 27, 1953 I5 Sheets-Sheet 1 Fig.|.

WITNESSES INVENTOR Robert E. Friedrich.

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38c. 4, 1956 R. E. FRiEDRiCi-l 2,773,155

CIRCUIT INTERRUPTER Filed Nov. 27, 1953 3 Sheet $611661 2 Dec. 4, 1956R. E. FRIEDRICH CIRCUIT INTERRUPTER Filed Nov. 27, 1953 Fig.4.

5 Sheets-Sheet 3 United States Patent F CIRCUIT INTERRUPTER Robert E.Friedrich, Pittsburgh, Pa., assignor to Westinghouse ElectricCorporation, East Pittsburgh, Pa., a corporation of PennsylvaniaApplication November 27, 1953, Serial No. 394,578

15 Claims. (Cl. 200--150) This invention relates to circuit interruptersin general, and more particularly to arc-extinguishing structures forcircuit interrupters of the fluid-blast type.

A general object of my invention is to provide an improved circuitinterrupter which will effect a more rapid and effective opening of thecircuit therethrough than has been obtained heretofore.

A more specific object of my invention is to provide an improved circuitinterrupter in which a valve struc ture is utilized to control auxiliaryventing passages, and operation of the valve structure is effected earlyin the operation, preferably prior to contact parting.

Still another object is to provide an improved circuit interrupterutilizing a series solenoid coil serially connected in the circuit, withmeans for employing the coil to effect operation of the valve structurecontrolling one or more auxiliary venting passages.

In U. S. Patent 2,752,460, issued June 26, 1956, to Winthrop M. Leeds,and assigned to the assignee of the instant application, there isdisclosed a circuit interrupter of the fluid-blast type involving avalve structure which controls auxiliary venting during the interruptionof highamperage currents. The operation of the valve structure isresponsive to the pressure within the interrupter.

It is a further object of my invention to improve the interruptingstructure set out in the aforesaid patent by eliminating any time delayfor the building up of pressure for operation of the valve structure,and preferably actuating such a valve structure prior to the separationof the contacts to establish arcing.

Further objects and advantages will readily become apparent upon'readingthe following specification, taken in conjunction with th drawings, inwhich:

Figure 1 is a side elevational view, partially in substantially verticalsection, of a circuit interrupter embodying my invention, the contactstructure being shown in the closed-circuit position;

Fig. 2 is a sectional view taken along the line llII of the interrupterillustrated in Fig. 3;

Fig. 3 is an enlarged vertical sectional view through one of thearc-extinguishing units depicted in Fig.1, the contact structure beingillustrated in the partially opencircuit position, and in thisparticular instance the adjacent valve structure is not being operatedbecause of the relatively low-value current being interrupted; and,

Fig. 4 is a vertical sectional view through a modified type ofarc-extinguishing unit embodying the principles of my invention, thecontact structure being shown in the partially open-circuit position andthe valve structur having been actuated to provide auxiliary venting ofthe interrupter.

Referring to the drawings, and more particularlyto Fig. 1 thereof, thereference numeral 1 designates a tank filled to the level 2 with asuitable arc-extinguishing fluid 3, in this instance circuit-breakeroil.

Depending from the cover 4 of the tank 1 is a pair of terminal bushings5, 6 to the lower ends of which Patented Dec. 4, 1956 ar threadedlysecured and clamped identical arc-extinguishing units, generallydesignated by the reference numeral 7. Electrically interconnecting thearc-extinguishing units 7 is a conducting cross-bar 8, verticallyactuated in a reciprocal manner by an insulating operating rod 9, thelatter being actuated by any suitable operating mechanism (not shown).

Referring to Figs. 2 and 3, which more clearly illustrate the internalconstruction of th extinguishing unit 7, it will be observed that thereis provided a conducting adapter 11, which is threadedly secured andclamped, by a clamping bolt 12, to the lower end of the terminal stud 13extending internally through the terminal bushing 5. Integrally formedwith the adapter 11 is a support plate 14, composed of a conductingmaterial and preferably formed with the adapter 11. An actuatingsolenoid 15 is electrically connected between the support plate portion14 and the top dome casting 16 of the extinguishing unit 7. The top domecasting 16 is insulated from the plate portion 14 by an insulating plate17 and secured thereto in any suitable manner, such as by insulatedbolts (not shown).

Pivotally mounted within the top dome casting 16 is a rotatablypressure-generating contact 18 pivotally mounted, as at 12, andexternally actuated by a side insulating operating rod 20. The operatingrod 20 is biased downwardly in a circuit opening direction by acompression spring 21 having its lower end seated upon a cap 22 securedto the lower end of the operating rod 20.

During the closing operation the cross-bar 8 moves upwardly intoabutting engagement with the cap 22, compressing th spring 21, andforcing the operating rod 20 upwardly to cause pivotal closing motion ofthe pressure-generating contact 18 into engagement with an intermediatecontact, designated by the reference numeral 24. The intermediatecontact 24 has a flange portion 25 which makes engagement with a plate26 to limit the downward opening movement of the intermediate contact24. A spring 27, having its lower end seated upon the flange portion 25,and having its upper end bearing against a plate 28, tends to bias theintermediate contact 24 downwardly. Cooperating with the intermediatecontact 24 is a lower movable interrupting contact 29, in thisparticular instance constituting an extremity of the cross-bar 8, whichis turned upwardly, as shown in Fig. 3 of the drawings.

A pin 30 extends through the upper end of the operating rod 20 and alsopasses through a pair of apertures 31 provided in a pair of actuatingarms 32 forming integral extensions of the pressure-generating contact18. A washer 33 slides upon the operating rod 20 and abuts against thelower sides of the actuating arms 32, as shown in Fig. 3. A contactcompression spring 34 is interposed between the washer 33 and a secondwasher 35, which is rigidly alfixed to, and movable with, the sideoperating rod 20.

Thus, during the closing operation the operating rod 9 moves upwardly,carrying with it the cross-bar 8 and the lower movable interruptingcontacts 29. The cross-bar 8 picks up the two operating rods 20,compressing the springs 21, and effecting closing rotative motion of thepressure-generating contacts 18. The tip portion 37 of the interruptingcontact 29 strikes the intermediate contact 24 prior to thepressure-generating contact 18 striking the upper end 38 of theintermediate contact 24, thereby slightly compressing the spring 27. Inthe meantime the pin 30 has raised slightly within the apertures 31cornpressing the spring 34, which provides the requisite contactpressure between the several contacts.

During the opening operation, as will be obvious, the

lift-rod 9 and the cross-bar 3 move downwardly in respouse to theoperation of the circuit-breaker mechanism (not shown). Because of thecompression sprlng 21 the side operating rod moves downwardly so thatthe cap 22 remains in abutting engagement with the cross-bar 8, causingupward separating motion of the pressure-generating contact 18 away fromthe intermediate Contact 24 at substantially the same time that thelower movable interrupting contact 29 separates therefrom.

This results in the establishment of two serially related arcs, as shownin Fig. 3, the upper one being a pressuregenerating are 39, establishedwithin the pressure-generating chamber 46, and the lower one being aninterrupting are 41, established along an arc passage 42 defined by aplurality of contiguously disposed plates.

The pressure-generating are 39 sets up pressure within the oil, whichcompletely fills the unit '7, and causes a downward flow of oil withinthe conduit 43, the disposition of which is more clearly apparent froman inspection of Fig. 2 of the drawings. Leading from the conduit 43 areinlet passages 44 directing fluid, in this instance oil, toward the arcpassage 42. The conduit 43 is formed by apertures 45 provided in theseveral plates making up the extinguishing unit 7. The inlet passages 44are provided by removing portions of plates 46, herein called inletplates. On the upper and lower side of each inlet plate 46 is an orificeplate, designated by the reference numeral 47, and having an aperture 48therein only slightly larger than the movable interrupting contact 29.On the other side of the orifice plate 47 is a vent plate, generallydesignated by the reference numeral 49, and comprising two plate-halves49a and 49b, spaced laterally apart to provide thereby opposed ventingpassages 50.

During the interruption of load currents and relatively low value faultcurrents the normal functioning of the interrupter 7 is such that theliquid flow travels downwardly through the vertically disposed conduit43, inwardly through the inlet passages 44, and into engagement with theinterrupting are 41. The fluid, in this instance oil, then passesthrough the apertures 48 in the orifice plates 47 to pass outwardlythrough the venting passages 50 to the region externally of theextinguishing unit 7. Circuit interruption soon follows, and thecross-bar 8 separates downwardly away from the cap portions to anisolating position, indicated by the dotted lines 51 in Fig. 1.

During the interruption of fault currents, or currents of high amperage,it is desirable to provide additional venting for assisting ininterruption of the interrupting are 41 and to relieve the internalpressure within the extinguishing unit 7. For this reason, I provideauxiliary venting passages 52, which normally are closed by a valvestruc ture 53, as indicated in Figs. 2 and 3. The valve structure 53comprises a plurality of superimposed valve elements 54 secured to andmovable with a valve rod 55, and biased downwardly by a compressionspring 56 to a closed position. The valve rod 55 is preferably formed ofinsulating material and has afiixed thereto at its upper end an armature57 threading the solenoid 15 and actuated thereby.

During the interruption of high-fault currents, even before the contacts18, 24 and 29 separate, the coil 15 will be responsive to the faultcurrent and will effect upward movement of the valve rod 55 and thusopening of the several venting passages 52. As a result, there willoccur a cross-blast action across the are 41 in addition to the normalfluid flow as heretofore described.

Actuation of the valve structure 53 will, therefore, not only serve torelieve the pressure within the interrupter 7, but will also provideadditional interrupting fluid-blast action across the are 41. The valvestructure 53 has the advantage over the valve structure of the aforesaidpatent in that it is immediately actuated, without any delay, and evenprior to the separation of the contact structure. The result, therefore,is an extremely fast acting interit rupter 7, bringing about veryhigh-speed interruption of the circuit.

Fig. 4 shows a modification of my invention in which the valve structure58 is spring-biased downwardly to an open position by a compressionspring 59, and is latched in its upper position by a latch 60, which iselectromagnetically actuated. In other words, a solenoid 15a responsiveto the series current passing through the interrupter actuates thearmature 61 to effect pivotal releasing action of the latch 60, causingthe nose 62 thereof to clear the hook-portion 63 disposed at the upperend of the valve rod 55a. During the closing operation, an extension 64of the cross-bar 8a picks up the cap 65 and relatches the valvestructure 58. The latch 6b is biased by a spring 70 in acounter-clockwise direction about its pivot 67 to a limiting position,as determined by the stop 71. During closing, the nose 63 of rod 55amoves the latch 60 to one side so that the valve structure 58 isrelatched.

The arrangement illustrated in Fig. 4 has the advantage over that ofFigs. 2 and 3 since the solenoid 15a need not be designed to perform theenergy requirements required of the solenoid 15 in Fig. 3. Only arelease of the latch 60 is required of the solenoid 15a in Fig. 4. Asshown, a bracket 66 pivotally supports the latch, as at 67 and has anupper guide portion 68 to guide the armature .61. The internalconstruction of the modified unit 67 is otherwise the same as in theconstruction set out in Figs. 2 and 3; consequently, the operation willnot be repeated.

From the foregoing description of my invention, it will be apparent thatI have provided an extremely highspeed and effective circuit interrupterin which auxiliary venting passages are opened up during theinterruption of high-amperage currents to relieve the pressure and toassist in arc interruption by providing a desired trans versecross-blast action. I have illustrated two arrangements forelectromagnetically causing the actuation of the valve structures 53,58.

Although I have shown and described specific structures, it is to beclearly understood that the same were merely for the purpose ofillustration, and that changes and modifications may readily be madetherein by those skilled in the art, without departing from the spiritand scope of the invention.

I claim as my invention:

1. A circuit interrupter of the fluid-blast type including separablecontact means for establishing an are, a first venting means, means forsending a flow of fluid against the arc and out the first venting means,auxiliary second venting means, valve structure normally closing thesecond venting means, and electromagnetic means responsive to theaverage value of the current passing through the interrupter during theperiod the contact means is separating to effect opening of the valvestructure at a predetermined average current magnitude during the timethe arc is established.

2. A circuit interrupter of the fluid-blast type includ ing anarc-extinguishing unit, means for establishing an are within the unit, afirst venting means, means for sending a flow of fluid against the arcand out the first venting means, auxiliary second venting means, valvestructure normally closing the second venting means, a solenoid mountedon the arc-extinguishing unit and responsive to the average seriescurrent passing through the interrupter, an armature, meansinterconnecting at tractive motion of the armature with opening of thevalve structure, and the valve structure opening during the time the arcis established.

3. A circuit interrupter of the fluid-blast type including means forestablishing an arc, operating means for effecting the actuation of saidmeans, a first venting means, means for sending a flow of fluid againstthe arc and out the first venting means, auxiliary second venting means,valve structure normally closing the second venting means, latchingmeans for the valve structure latching it in the closed position, andelectromagnetic means independent of the operating means and responsiveto the average value of the current passing through the interrupter toeffect release of the latching means at a predetermined average currentmagnitude.

4. The combination in a circuit interrupter of separable contact meansfor establishing a pressure-generating arc and a serially relatedinterrupting arc, means utilizing the pressure established at thepressure-generating arc to force fluid toward the interrupting arc, afirst venting means for the interrupting are which is normally open, asecond venting means for the interrupting arc, valve means for normallyclosing the second venting means, and electroresponsive means responsiveto the average current passing through the interrupter during the periodthe contact means are separating to cause opening of the second ventingmeans.

5. A circuit interrupter of the fluid-blast type including anarc-extinguishing unit, means for establishing a pressure-generating arcand an interrupting are within the unit, an interrupting structuredisposed adjacent the interrupting arc and having a first venting meansassoci ated therewith, a first fluid-transmitting passageinterconnecting the pressure-generating arc with the interruptingstructure, a second venting means, a second fluid-transmitting passageleading from the interrupting structure to said second venting means,valve means normally closing the second venting means, andelectroresponsive means mounted on the arc-extinguishing unit andresponsive to the average series current passing through the interrupterfor actuating the valve means at a predetermined average current.

6. A circuit interrupter of the fluid-blast type including anarc-extinguishing unit, separable contact means for establishing apressure-generating arc and an interrupting are within the unit, aninterrupting structure disposed adjacent the interrupting arc and havinga first normallyopen venting means associated therewith, a firstfluidtransmitting passage interconnectingthe pressure-generating arcwith the interrupting structure, a second normallyclosed venting means,a second fiuid-transmitting passage leading from the interruptingstructure to said second venting means, valve means for controlling theopening of the normally closed venting means, and electro-responsivemeans responsive to the average series current passing through theinterrupter during the period the contact means are separating foropening said valve means at a predetermined current.

7. A circuit interrupter of the liquid-blast type including anarc-extinguishing unit, means for establishing a pressure-generating arcand an interrupting are within the unit, an interrupting structuredisposed adjacent the interrupting arc and having a first venting meansassociated therewith, a first liquid-transmitting passageinterconnecting the pressure-generating arc with the in terruptingstructure, a second venting means, a second liquid-transmitting passageleading from the interrupting structure to said second venting means,valve means for controlling the second venting means, a solenoidresponsive to the series current passing through the interrupter, anarmature, and means interconnecting the armature with the valve means sothat at a predetermined current the solenoid will effect movement of thearmature and open said valve means.

8. A circuit interrupter of the fluid-blast type including anarc-extinguishing unit, means for establishing a pressure-generating arcand an interrupting are within the unit, operating means for effectingthe actuation of said means, a multi-orifice interrupting structuredisposed adjacent the interrupting arc and having a first venting meansassociated therewith, a first fluid-transmitting passage interconnectingthe pressure-generating arc with the multi-orifice interruptingstructure, a second venting means, a second fluid-transmitting passageleading from the multi-orifice interrupting structure to said secondventing means, valve means normally closing the second venting means,and electroresponsive means independent of the operating means andresponsive to the series current passing through the interrupter toeffect opening of the valve means at a predetermined current.

9. A circuit interrupter including an arc-extinguishing unit immersed inan arc-extinguishing liquid, a movable pressure-generating contactseparable from a relatively stationary intermediate contact to establisha pressure-generating arc, an arcing passage, a rod-shaped movableinterrupting contact separable from said intermediate contact along saidarcing passage to establish an interrupting arc progressively along saidarcing passage, operating means for actuating said contacts, a pluralityof inlet passages leading into said arcing passage, meansinterconnecting the inlet passages with the pressure-generating arc, anormally open first venting means communicating with the arcing passage,a plurality of spaced exhaust passages leading away from the arcingpassage, a second venting means connecting the exhaust passages with theregion exteriorly of the unit, valve means controlling the secondventing means, and electroresponsive means independent of the operatingmeans and responsive to the series current passing through theinterrupter for opening said valve means at a predetermined current.

10. A circuit interrupter including an arc-extinguishing unit immersedin an arc-extinguishing liquid, 21 movable pressure-generating contactseparable from a relatively stationary intermediate contact to establisha pressure-generating arc, an arcing passage, a rod-shaped movableinterrupting contact separable from said intermediate contact along saidarcing passage to establish an interrupting arc progressively along saidarcing passage, operating means for actuating said contacts, a pluralityof inlet passages leading into said arcing passage, meansinterconnecting the inlet passages with the pressure-generating arc, anormally open first venting means communicating with the arcing passage,a plurality of spaced exhaust passages leading away from the arcingpassage, a slide valve normally closing the exhausting of liquid outthrough the exhaust passages, and electroresponsive means independent ofthe operating means and responsive to the series current passing throughthe interrupter for actuating the slide valve and so opening the exhaustpassages at a predetermined current.

11. A circuit interrupter of the fluid-blast type including a casing,means for establishing an are within the casing, operating means foreffecting the actuation of said means, a first venting means leading outof the casing, means for establishing pressure within the casing forsending a flow of fluid against the arc and out of the casing throughthe first venting means, auxiliary second venting means leading out ofthe casing, valve structure normally closing the second venting means,and electromagnetic means independent of the operating means andresponsive to the average value of the current passing through theinterrupter to effect opening of the valve structure at a predeterminedaverage current magnitude.

12. A circuit interrupter of the fluid-blast type including a casing,means for establishing an are within the casing, a first venting meansleading out of the casing, means for establishing pressure within thecasing for sending a flow of fluid against the arc and out of the casingthrough the first venting means, auxiliary second venting means leadingout of the casing, valve structure normally closing the second ventingmeans, a solenoid mounted on the casing and responsive to the averageseries current passing through the interrupter, an armature, and meansinterconnecting attractive motion of the armature with opening of thevalve structure.

13. A circuit interrupter of the fluid-blast type including means forestablishing an arc, a first venting means, means for sending a flow offluid against the arc and out of the first venting means, auxiliarysecond venting means, valve structure normally closing the secondventing means, electromagnetic means responsive to the aver age value ofthe current passing through the interrupter and actuable only above apredetermined average current magnitude, and a direct, positiveconnection between the valve structure and the electromagnetic means toeffect opening of the valve structure every time the electromagneticmeans actuates.

14. A circuit interrupter of the fluid-blast type including anarc-extinguishing unit, means for establishing a pressure-generating arcand an interrupting are within the unit, an interrupting structuredisposed adjacent the interrupting arc and having a first venting meansassociated therewith, a first fluid transmitting passage interconnectingthe pressure-generating arc with the interrupting structure, a secondventing means, a second fluid transmitting passage leading from theinterrupting structure to said second venting means, valve meansnormally closing the second venting means, electromagnetic meansresponsive to the average value of the current passing through theinterrupter and actuable only above a predetermined average currentmagnitude, and a direct, positive connection between the valve means andthe electromagnetic means to effect opening of the valve means everytime the electromagnetic means actuates.

15. A circuit interrupter of the fluid-blast type including anarc-extinguishing unit, means for establishing a pressure-generating arcand an interrupting are Within the unit, means defining a substantiallyenclosed elongated arc passage Within which the interrupting .arc isdrawn and having one or more laterally disposed venting passagesdisposed therealong, a first fluid transmitting passage interconnectingthe pressure-generating varc with the substantially enclosed arcpassage, one or more second laterally disposed venting passages leadingout of the arc passage, valve means normally closing said one or moresecond laterally disposed venting passages, electromagnetic meansresponsive to the average value of the current passing through theinterrupter and actuable only above a predetermined average currentmagnitude, and a direct, positive connection between the valve means andthe electromagnetic means to effect opening .of the valve means everytime the electromagnetic means actuates.

References Cited in the file of this patent UNITED STATES PATENTS

